This invention relates to a device for reducing the effective length of a spring for providing a load, for example, on a dancer roller used for absorbing slackness in a web.
The film-transporting mechanism for a packaging machine shown in FIG. 4, for example, utilizes a dancer roller 25 on which a specified load is applied by means of a spring so as to absorb slackness in a web of package-forming material S which may occur while it is being transported on its travel path. Since the distance traveled by a dancer roller of this kind is generally quite large, a spring with a fairly large total length must be used if it is to be directly attached to the roller without using a lever. This makes it difficult not only to reduce the size of the device as a whole but also to stably carry out the function of absorbing slackness in the package-forming material.
The present invention has been accomplished in view of such problems. It is therefore an object of this invention to provide a new device for reducing as much as possible the effective length of a spring used for providing a load.